Nowadays, a liquid crystal display (LCD) has been dominant in the panel display market for its advantages of small size, low power consumption, low radiation, and the like. In order to display an image on a screen of the LCD, it is necessary to configure a backlight unit (BLU) for a display panel. This is because the liquid crystals in the LCD can not emit light by themselves, and the liquid crystals just regulate light.
In general, the BLUs may be categorized into side-edge backlight units and direct-type backlight units according to the distribution positions of light sources in the BLUs. A light source in the side-edge backlight unit is positioned at a side of the display panel, and a light source in the direct-type backlight unit is positioned at the bottom of the display panel. The side-edge backlight unit is widely used due to its advantages of low cost, thin profile etc.
The existing side-edge backlight unit generally includes a light guide plate and a light-emitting device arranged at a side of the light guide plate. As shown in FIG. 1, the light-emitting device in the prior art includes a U-shaped lampshade 11 and at least one light source 33 arranged on the inner bottom of the U-shaped lampshade 11 via a printed circuit board (PCB) 22. When the light source 33 is formed of a Light Emitting Diode (LED), due to the limitation of a LED's own conditions such as a light-emitting angle (which is generally 120 degrees), light intensity at the central region of light emitted from each LED is higher. Thus, brightness at a corresponding position on the light guide plate is larger. Light intensity at the intersection region of light emitted from two adjacent LEDs is lower. Thus, brightness at a corresponding position on the light guide plate is smaller. Therefore, the intersection region of light emitted from two adjacent LEDs will result in a Hotspot phenomenon (i.e., a phenomenon of non-uniform brightness) on the light guide plate and form dark areas, thus image quality is affected.